Weapon systems have been undergoing development for a considerable period of time and in recent years, substantial improvements have been made which enable various types of weapons to be employed more effectively by reducing the human skills required in the various facets of their operation. As an example U.S. Pat. No. 3,548,212 discloses a device which utilizes a multi-beam laser to lock onto and track an intended target. In the arrangements shown in this patent, a reflected laser beam is utilized to operate a servo and bring a gun mounted in a vehicle into alignment with and then lock on to a moving target. Another device as disclosed in U.S. Pat. No. 3,457,827, relies upon the sensing of infra-red radiation emitted from an intended target to home a gun on the target and provide an indication to the gun operator of the optimum time for firing the gun.
However, with the advent of modern versions and derivatives of rapid fire automatic weapons generally referred to as "Gatling" guns considerations unique to the use of the type of weapon have been brought into sharper focus. Such modern day versions of these weapons are not only capable of firing projectiles of considerable size, but also have the capability of firing as much as four thousand rounds of such ammunition per minute through a multiplicity of rotating gun barrels. While it can be readily appreciated that such massive and concentrated firepower will have a devastating effect upon its targets, huge quantities of ammunition are expended. Thus the operation of weapons of this type is not only costly, but impose severe and difficult logistic burdens as well.
In addition, when such weapons are situated in combat vehicles such as tanks, aircraft, ships and boats, the weapon carrier must contain suitable provisions to accommodate the vast quantities of ammunition that such weapons can expend in order that they might be effectively used.
Moreover, when weapons of this type are mounted in certain of these vehicles and aircraft in particular, the weight of a sufficient quantity of ammunition to enable the use of the weapon in the most effective manner will often account for a substantial percentage of the aircraft's payload capability. Consequently, serious compromises will oftentimes be made with respect to making determinations as to the quantities of ammunition and fuel load or in the provision of additional weaponry or ordnance as might otherwise be carried aboard the aircraft to enhance its mission capabilities. Once committed to such pre-determined decisions as to weapon mix and fuel load, the aircraft's mission profile is well established. Consequently, the mission flexibility of the aircraft once in progress is substantially reduced and its ability to respond to changing circumstances or combat situations that assume a different complexion is somewhat hampered. As an example, if in making such judgments it is determined that the fuel portion of the payload is to be reduced to favor an increase in the amount of ammunition for a rapid fire gun of the type mentioned above, or other ordnance is to be carried on a given mission, the aircraft's operating range or loiter time over suspected targets will understandably be reduced. In view of this, improving the effectiveness of the weapon systems by improving its accuracy is absolutely essential in that it will result in a smaller quantity of ammunition which will be required during a mission to achieve the desired results.
In the case of rapid fire weapons of the type mentioned above and referred to as the "Gatling" gun, improved accuracy in the use of the weapon would be reflected in the quantity of ammunition that had to be expended in order to neutralize a target. However, despite improvements which might be made in the accuracy of these weapons, the manner in which they are ordinarily used is a major factor in their consumption of ammunition. In this connection, it is customary when firing such weapons to spray the target area with gun fire. In the case of a rapid fire guns mounted in a vehicle such as an aircraft, and particularly in those aircraft equipped with fixed forward pointing guns that require that the aircraft be pointed at the intended target, the fire from guns is ordinarily "walked" across the target area to assure that a number of rounds will in fact strike the target. In practice this means that a considerable quantity of ammunition must be expended of which only a small percentage will at best, actually strike the target. Understandably, as the rate of fire of each particular gun increases, so too does the amount of ammunition ineffectively consumed in this manner. This ineffective use of ammunition has been substantiated and graphically illustrated by film frames taken of typical low angle strafing runs of aircraft having fixed forward facing, rapid fire "gatling" type guns. Examination of such films and correlation with the action of the gun operator reveal that the gunsight pipper, which is known to those skilled in the art as the reference dot within a gunsight, was held on an estimated 50 square foot target for only 0.2 to 0.3 seconds per successful strafing run, or for about 30% of a one second firing burst. This time is of course not absolute, but a representative sample based upon such things as the function of aircraft controllability and stability and the simple reaction time for an average 25 year old combat trained aircraft pilot/gun operator squeezing the trigger when the target appears in the gun sight.
This procedure results in a considerable miss probability so it is not an uncommon practice to compensate for the reaction time and some of the other variables, as well as the abbreviated time during which the target appears in the gunsight reticle by firing early, that is, before the target appears in the reticle and continuing to fire so as to "walk into" the target. While this technique improves the hit probability without question, the quantity of ammunition which misses the target and is therefore "wasted" is tremendous.
To fully appreciate several other important aspects of these wasteful practices, the weight and cost of the ineffective ammunition must also be considered. In this connection and based upon the observations of the film frames mentioned above, the wasted portion of a one second gun fire burst of 30 millimeter ammunition can be translated to a weight of 1470 pounds and a cost of $14,200. These figures are based upon 1350 total rounds of ammunition.times. 70%.times. 1.56 1b/per round at a cost estimated conservatively at $15 per round. As could be expected, as the gun fire burst time increases, so too does the amount of ammunition ineffectively consumed and along with it the attendant increase in its cost and weight of the larger percentages of wasted ammunition.
Perhaps even more importantly, when the aforementioned gunnery techniques are used under certain combat conditions, unintended, but substantial risks to friendly forces are often incurred. In this connection, rapid fire weapons of the type being discussed are most effective against positions, such as entrenchments, armored vehicles and the like and are frequently used against them in support of friendly ground forces. Under such conditions aircraft equipped with these guns often conduct strikes against these targets in support of friendly ground forces located or moving in proximity to the intended target. As a consequence those ground forces are exposed to the real danger of being fired upon unintentionally by the gun operator. Another major disadvantage arises from the fact that oftentimes in such combat circumstances the firing of the gun may be deliberately delayed as a precautionary measure to minimize the danger to those ground forces, lessening even further the likelihood of striking the intended target and diminishing even further the effectiveness of the gun fire. Moreover, with the heightened possibilities that the target will not be neutralized on the first pass, due to the ineffectiveness of the gun fire, an additional pass or passes may be necessary to satisfy the mission requirements, increasing the risks that are coincident with repeated exposures to hostile action. Obviously, such repeated passes no longer have the advantages of surprise and are more likely to encounter marshalled countermeasures that have been alerted, subsequent to the initial strike of the attacking aircraft.